Eleocharis palustris Common Spike-rush CCC DD N
The plants of this genus have few features to use for identification. It is fairly easy to place them as Eleocharis but trickier to tell one from the other. This one being the commonest is fairly tall sometimes over 0.5m.
Although a quite insignificant plant, E. palustris has been recorded from almost everywhere in the British Isles and Ireland.